hi @hazquin beforeyou can apply for migration, you should be finished with stage 1 or desktop assessment of your qualification from the OT council.
"On completion of the Stage 1 desktop assessment, the occupational therapist will be advised in writing of the suitability of qualifications for the purpose of applying for skilled migration. A certified copy of this assessment letter should be provided with your application for migration purposes to the Department of Immigration and Border Protection (DIBP)."
https://www.otcouncil.com.au/assessment/assessment-overseas/
You can take IELTS or PTE. Good luck!